| 摘要 |
1484641 Bonding by brazing GOULD Inc 10 March 1975 [13 March 1974] 9945/75 Heading B3R In a method of bonding sintered iron containing articles, the articles are treated to oxidize the pores of the sintered iron to form Fe 3 O 4 , preventing or removing oxide formation on the faying surfaces and then forming a metallurgical bond, e.g. by interposing brazing filler material between the faying surfaces and heating the articles to melt the filler material to produce the bond. The articles are treated by the application of dry steam at a temperature in the range of 300‹ C. to 570‹ C. to produce the Fe 3 O 4 . The faying surfaces may be masked during this step by a slurry of graphite and alcohol, or the oxide produced on the faying surface can, be removed by fluxing, acid dip, or grinding. The articles may comprise at least 51% iron, and copper, nickel and other alloying elements. From 5% to 20% of the iron may be converted to Fe 3 O 4 . Examples of brazing fillers, as a paste or a shim, are disclosed, and brazing fluxes containing chlorides, fluorides, borates, or boric acid, borates, fluorides, fluoborates are referred to. |
